Indonesia lies on both sides of the equator and therefore has a typical tropical climate with two seasons - dry and rainy.
However, due to the vast size of Indonesia, these seasons vary greatly across regions. So while Bali's dry season peaks in August, Raja Ampat, for example, has the least rain between December and February.
Find out the prices of flights to Indonesia in high season
However, this doesn't mean that it doesn't rain at all in the dry season and all the time in the rainy season. During the rainy season, heavy rains come at various intervals, often followed by the sun coming out again for a few hours or days.
Temperatures throughout Indonesia hover around 30 °C all year round with high humidity.
It can be cooler at higher altitudes, which is especially noticeable at night. Therefore, when climbing volcanoes, be sure to pack warmer clothing, as it can be less than 10°C on the peaks.
Due to its equatorial location, days and nights are roughly equal in length, with dawn breaking around 5.30pm and darkness returning after 6pm.
Indonesia during the year
What is the weather like in Indonesia in each month?
Weather in January
January is the rainy season mainly in the southern half of Indonesia. For the islands of Bali, Java, Komodo, South Sumatra and others, January is the rainiest month of the year.
Heavy and frequent downpours are replaced by semi-cloudy or clear weather, however, due to the high humidity this period is not very suitable for mountain trekking.
Raja Ampat, North Sumatra (Lake Toba)
Weather in February
During February, the rainy season persists in the southern half of Indonesia, while the northern regions enjoy mostly partly cloudy skies with only light showers.
Raja Ampat, North Sumatra (Lake Toba)
Weather in March
The rainy season slowly comes to an end in March, but especially in the first half of the month it still rains very often and very heavily.
Expect that jungle trips and mountain treks may not be feasible.
North Sumatra and the Raja Ampat region, on the other hand, still remain rainy.
Raja Ampat, North Sumatra (Lake Toba)
Weather in April
April is a transitional month between the m rainy and dry seasons. The weather is changeable virtually all over Indonesia.
Heavy rains can still occur, but the rain-free period can last for several days in April.
In the popular diver's paradise of Raja Ampat, on the other hand, the rainy season begins, but there is still a good chance of good visibility below the surface in April.
Where to go: similar weather across Indonesia
Weather in May
During May, the dry season begins in the southern half of Indonesia.
It can rain heavily, but showers are usually very brief and do not occur every day. In Raja Ampat, on the other hand, the rainy season begins.
Where to go: Bali, Java, Lombok, Komodo, Borneo, South Sumatra, Sulawesi
Weather in June
June begins the high season for travel to most of Indonesia.
The dry season prevails, with temperatures rising to an average of 32°C, but humidity is lower than during the rainy season and rain is very sporadic.
Where to go: Bali, Java, Lombok, Komodo, Borneo, all of Sumatra, Sulawesi
Weather in July
The dry season continues in July for the vast majority of Indonesia with very little rainfall and lower humidity.
However, for the Raja Ampat region, July is one of the main rainy seasons.
Where to go: Bali, Java, Lombok, Komodo, Borneo, South Sumatra, Sulawesi
Weather in August
August is statistically the least rainy month of the year.
In Java or Bali, for example, it hardly rains at all and light showers are rare. August is therefore the best month for mountain trekking, jungle trips and beach holidays.
Where to go: Bali, Java, Lombok, Komodo, Borneo, South Sumatra, Sulawesi
Weather in September
September is still one of the peak months of the dry season with little rainfall. If rain does occur, it usually lasts for no more than an hour.
The rainy season is slowly ending on Raja Ampat, but this month is still not one of the best when it comes to diving and snorkelling.
On the other hand, in North Sumatra around Lake Toba, the rainy season begins, when the rain is often very heavy.
Where to go: Bali, Java, Lombok, Komodo, Borneo, South Sumatra, Sulawesi
Weather in October
October is the last month of the dry season for most of Indonesia.
Although it may rain more frequently towards the end of the month, the whole of October still counts as the high season.
In North Sumatra, the rainy season peaks and conversely, in Raja Ampat, the rainy season ends.
Where to go: Bali, Java, Lombok, Komodo, Borneo, South Sumatra, Sulawesi
Weather in November
While the heavy downpour season slowly begins in the southern part of Indonesia, the high season starts in the diving paradise of Raja Ampat.
Where to go.
Weather in December
December is the first real month of the rainy season for most of Indonesia. While mountain treks may be inaccessible, this weather need not be a barrier to visiting cities, sights, as well as rice terraces and beaches.
In fact, in between showers it often clears to clear skies.
Where to go.
Table of temperatures during the year
Bali - The tourist idol of Indonesia
When to go to Indonesia
Generally speaking, the best time to travel is April to September. This is what most travellers think, so expect higher prices for services and accommodation and crowds of tourists. You can also travel during the rainy season, but you need to improvise more depending on the weather. For this option, it is better to choose the more eastern islands, which tend to be affected by the Australian monsoons. Be sure to remember a raincoat or umbrella in this option.
If you can, avoid travelling around Indonesia during Ramadan, especially as Idul Fitri approaches. Millions of people are on the move at that time, those going to visit their distant relatives. You probably won't eat during the day during this month, as Muslims may not eat until nightfall and shops and eateries are often closed during the day.
You are unlikely to be able to stay, as accommodation, especially the cheaper ones, is often desperately busy. And you won't be able to move, as tickets and seats for all means of transport for the next few days are hopelessly sold out. Not to mention the insane traffic jams, which - although it already seems impossible - become even worse during the Lenten month, so that even if you do happen to get a ticket, you will spend an inordinate amount of time on the road.
